Slide-valve for engines



(No Model.)

0. L. WARD. I SLIDE VALVE FOR ENGINES. No. 434,367. Patented Aug. 12,1890.

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E I ATTORNEYS.

4 UNITED STATES PATENT OFFICE.

OSCAR L. IVARD, OF EAGLE, NEBRASKA.

SLIDE-VALVE FOR ENGINES.

v SPECIFICATION forming part of Letters Patent No. 434,367, dated August12, 1890. Application filed April 4, 1890- Serial No. 346,646. (Nomodel.)

To all whom it may concern:

Be it known that I, OSCAR L. WARD, of Eagle, in the county of Cass andState of Nebraska, have invented a new and Improved Slide-Valve forEngines, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved slide-valvefor steam-engines which is simple .and durable in construction andperfectly counterbalanced, so as to reduce the wear to a minim um.

The invention consists of a valve provided with intersecting slots.

The invention also consists of certain parts and details andcombinations of the same, as will be hereinafter fully described, andthen pointed outin the claims.

Reference is to-be had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in allthe figures.

Figure 1 is a plan view of a steam-engine provided with the improvement.Fig. 2 is a transverse section of the same on the line a: 00 of Fig. 1.Fig. 3 is a sectional plan view of the same on the line y y of Fig. 2.Fig. 4 is a rear sectional elevation of the same on the line 2 z of Fig.3, and Fig. 5 is a perspective view of the slide-Valve. v

The engine A, to which the slide-valve is applied, is provided with thecylinder B, in which operates the piston 0, connected in the usualmannerwith the main driving-shaft D. From the ends of the cylinder Blead the two inlet-ports a and 1), opening into the steamchest E, inwhich is fitted to slide the valve F, actuated by suitable means fromthe main driving-shaft D- The slide-valve F is provided with avertically-arranged slot 0, connecting atits upper end at all times withthe steam-inlet pipe G. The slide-valve Fis also provided with atransversely-arranged slot cl, intersecting the slot 0 at right anglesand adapted to be connected alternately with the steam-inlet ports a andb. The steam-chest E is also provided near each end with theexhaust-ports e and f, leading to the outside, and the ends of thecylinder B are also connect-ed with the exterior of the steam-chest E bypipes H and I, respectively opening into the said steam-chest in linewith the respect ive ports a. and b.

arrow at.

The operation is as follows: When the piston O and the valve F are inthe position shown in Fig. 3, live steam passes through the inlet-pipe Ginto the vertically-arranged slot 0, from which the steam can pass tothe top and bottom of the slide-valve, so as to exert an equal pressureon the top and bot tom. The live steam also passes into thetransversely-extending slot d, so as to exert a pressure at each side,thus completely counterbalancing the valve, so that it only rests by itsown weight in the bottom of the steamchest E. The live steam passinginto the e slots 0 and d can pass from the latter slot through theinlet-port a into the outer end of the cylinder B, to exert its pressureagainst the piston O, in order to force the same in ward in thedirection of the arrow 0/. The steam in the inner end of the cylinder Bcan now exhaust through the port 1), leading into the steam-chest E,which is open at this end to the exhaust port f, through which theexhauststeam can escape. When the piston O nears the end of its inwardstroke, the valve F changes its position-that is, it moves inwardso asto disconnect the transverse slot 61 from the inlet-port a to connectthe said transverse slot d with the inlet-port b. At the same time theinlet-port a opens into the right-hand end of the steam-chest E,containing the exhaust-port e. Nowlive steam passing into the slots 0and d passes into the port I) to the inner end of the cylinder, to exertits pressure against the piston O to force the latter outward 'in theinverse direction of the The exhaust-steam in the outer end of thecylinder B passes through the port a to the outer end of the steam-chestE and 0 through the exhaust-port e to the outer air.

It will be seen that during the time the steam cuts off either the porta or b at the ends of the valve F pressure is exerted through therespective inlet-porta orb against the cutting- 5 off end of the valveFby the expanding steam in the cylinder; but this pressure against thevalve F is counterbalanced by the steam in the cylinder passing from therespective pipe H or I against the cutting-oft end of the valve I00 Fopposite the said port a or 17. Thus it will be seen that the valve F.is at all times completely counterbalanced, so that the weight. isreduced to a minimum. It will further be seen that the valve is Verysimple in construction and can be readily applied to all classes ofengines.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent- 1. A slide-valve provided with a slotextendingthrough it from top to bottom and with a second. slot extending throughit from side to side and intersecting the first-named slot,substantially as described.

2. The combination, with a cylinder provided with inlet-ports and asteam-chest into which the said ports open, of a slide-valve in thesteam-chest provided with a slot extending through it from top to bottomand registering at all times with the inlet of the steamchest, and witha second slot extending through it from side to side and intersectingthe first-named slot, the said second slot a1- ternately registeringwith the cylinder-ports, substantially as herein shown and described.

3. The combination, with a cylinder prochest opposite the entrance ofthe said in1et ports to equalize the cylinder-pressure on the saidslide-valve when the ports are cut off, substantially as shown anddescribed.

4. In a slide-valve, the combination, with a cylinder provided withinlet -ports and a steam-chest into which the said ports open, of aslide-valve in the steam-chest having intersecting slots extendingthrough it at right angles to each other, and pipes connecting the endsof the cylinder with the steam-chest opposite the inlet-ports of thesaid cylinder, substantially as herein shown and described.

OSCAR L. WARD.

Witnesses:

WM. M. STAUDLEY, H. H. FILSINGLER.

